High heat thermoplastics such as polyetherimides are known as outstanding high performance materials. Polyetherimides can have a high glass transition temperature (Tg) of 217° C., high modulus, and strength at elevated temperatures and excellent chemical resistance, according to ASTM D543-06. Polyetherimide has an amber color with yellowness index greater than 50. This physical characteristic of polyetherimide limits its colorability to dark colors and fairly light colors, but not to very light colors such as certain white colors. Further, polyetherimide has low impact strength at room temperatures.
Lower heat materials such as polycarbonates and modified versions thereof (example, but not limited to polycarbonate esters) have excellent colorability, high impact strength and very good flow properties. However, these materials have poor resistance to harsh chemical reagents, susceptible to environmental stress cracking, poor UV resistance for light colors and relatively lower strength and modulus compared to polyetherimides.
Thus there exists a need to have a polymer system that can combine the above challenging, but desirable characteristics, all-in-one such as a chemically resistant, high flow, white-colorable, and good impact performance.
Blends of polyetherimide and PC have been evaluated for higher heat, improved ductility, and flame retardance. However, the specific combination of a polymer system that simultaneously imparts excellent chemical resistance, according to ASTM D543-06, to harsh chemical reagents (e.g., concentrated sulfuric acid, phosphoric acid etc.), high flow (thin wall less than 1 mm), colorable to certain ‘white’ colors (defined by L, a, b values), being UV resistant (color shift dE (DE* or ΔE) less than 6-7 units after 300 hrs exposure to ASTM D4459) with good notched impact strength (minimum 50 J/m at 23° C./2 lb hammer weight at greater than 15 wt % TiO2 pigment loading levels) and environmental stress cracking resistance to many chemicals such as hand sanitizers, moisturizers, sunscreen, cooking oil, e.g., olive oils, hand creams, and the like.
Further, there is a clear need for plastic materials, in addition to possessing all of the above desired characteristics, to also be able to be metallized with a metal such as, but not limited to aluminum, preferably wherein the aluminum is deposited and anodized to provide desirable characteristics such as corrosion resistance and wear resistance, better adhesion to paints and dyes vs. bare metal.
However, most polymeric materials may not survive the various mechanical/chemical treatments (such as, but not limited to, pre-treatment, etching, milling, desmutting, anodizing, coloring, sealing) on the plastic material typically involved during the anodization process
For the foregoing reasons, there is a need for a plastic material that can possess the aforementioned desired characteristics as well as be able to endure the anodization process by maintaining it properties and structural integrity.